import java.util.Scanner;

public class Demo10 {
    public static void main(String[] args) {
        /**
         * switch 结构
         */
//        System.out.println("请输入操作序号:");
//        Scanner sc = new Scanner(System.in);
//        int option = sc.nextInt();
//        switch (option){
//            case 1:
//                System.out.println("执行查看操作");
//                break;
//            case 2:
//                System.out.println("执行修改操作");
//                break;
//            case 3:
//                System.out.println("执行删除操作");
//                break;
//            default:
//                System.out.println("操作错误");
//        }
        System.out.println("请输入你的选择:");
        Scanner sc = new Scanner(System.in);
        String option = sc.next();
        switch (option){
            case "a":
            case "A":
                System.out.println("优秀");
                break;
            case "b":
            case "B":
                System.out.println("良好");
                break;
            case "c":
            case "C":
                System.out.println("中等");
                break;
            default:
                System.out.println("差");
        }
    }
}
